Assessment of heat mining and hydrogeochemical reactions with data from a former geothermal injection well in the Malm Aquifer, Bavarian Molasse Basin, Germany

Baumann, Thomas; Bartels, J.; Lafogler, Mark; Wenderoth, Frank

doi:10.1016/j.geothermics.2016.11.008

Cited by 15 publications

(10 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hydrogeochemical models are applied in order to predict precipitation reactions in surface level facilities and hydraulic changes induced by hydrogeochemical reactions in the reservoir (e.g. Baumann et al 2017;Fritz et al 2010;Nitschke et al 2017;Reed 1989;Regenspurg et al 2015). These geochemical model concepts rest on four foundations (Moog et al 2015):…”

mentioning

confidence: 99%

Validation of hydrogeochemical databases for problems in deep geothermal energy

Hörbrand

Baumann

Moog³

2018

Geotherm Energy

Self Cite

View full text Add to dashboard Cite

Background Geothermal energy has acquired a key position in the mix of renewable energies due to its very effective heat supply and the ability to provide base load electrical energy. Many current model concepts addressing deep geothermal exploration focus on thermal, mechanical, and hydraulic interactions (e.g. Gholizadeh Doonechaly et al. 2016; Magnenet et al. 2014; Major et al. 2018; Yoon et al. 2014; Zhao et al. 2015), while neglecting hydrogeochemical effects. This is partly due to a lack of experimental data for short-term hydrogeochemical processes in the vicinity of production and injection wells (Baumann Abstract Hydrogeochemical modelling has become an important tool for the exploration and optimisation of deep hydrogeothermal energy resources. However, well-established software and model concepts are often run outside of its temperature, pressure, and salinity ranges. The core of the model codes are thermodynamic databases which contain a more or less complete subset of mineral phases, dissolved species, and gases occurring in geothermal systems. Although very carefully compiled, they should not be taken for granted at extreme conditions but checked prior to application. This study compares the performance of four commonly used geochemical databases, phreeqc. dat, llnl.dat, pitzer.dat, and slop16.dat. The parameter files phreeqc.dat, pitzer.dat, and llnl.dat are distributed with PHREEQC and implement extended Debye-Hückel and Pitzer equations. Thermodynamic data in slop16.dat represent an implementation of the revised Helgeson-Kirkham-Flowers formalism and were converted to be used with the Gibbs Energy Minimizer ChemApp for this work. Test calculations focussed on the solubility for some of the most common scale-forming mineral phases (barite, celestite, calcite, siderite, and dolomite). The databases provided with PHREEQC performed comparatively well, as long as the range of validity was respected for which the corresponding database was developed. While it is obvious to use pitzer.dat at high salinities instead of phreeqc.dat, the range of validity for high temperature is usually not given in the database and has to be checked manually. The results also revealed outdated equilibrium constants for celestite in slop16.dat and llnl.dat and the lack of adequate temperature functions for the solubility constants of siderite and dolomite in all databases. For those two minerals, new thermodynamic data are available. There is, however, a lack of experimental thermodynamic data for scale-forming minerals in low-enthalpy geothermal settings, which has to be addressed for successful modelling.

show abstract

mentioning

confidence: 99%

Validation of hydrogeochemical databases for problems in deep geothermal energy

Hörbrand

Baumann

Moog³

2018

Geotherm Energy

Self Cite

View full text Add to dashboard Cite

show abstract

“…The isotopic composition of the aquifer water indicates significantly lower ambient temperatures compared to recent groundwater, thus putting the reservoir water into a glacial period. A full equilibrium with the matrix can safely be assumed for the reservoir fluids (Baumann et al 2017). The calculated bubble point for the reservoir water was 2.9 bar, thus we can assume that no gas phase is present under reservoir conditions.…”

Section: Hydrochemical Conditionsmentioning

confidence: 99%

“…Consequently, the carbonic-acid-equilibrium is shifted to higher pH and precipitation of carbonates occurs. In both cases, the presence of the air-water interface at the bubble has to be considered (Baumann 2016;Baumann et al 2017).…”

mentioning

confidence: 99%

Crystallization of calcium carbonate in a large-scale push–pull heat storage test in the Upper Jurassic carbonate aquifer

2020

Self Cite

View full text Add to dashboard Cite

The efficiency of geothermal power generation sites as well as aquifer thermal energy storage in carbonate aquifers is still affected by precipitations of calcium carbonate polymorphs (Lee 2013; Mundhenk et al. 2013; Ueckert and Baumann 2019). Precipitation of calcium carbonate in geothermal systems is mainly caused by temperature and pressure changes (Baumann et al. 2017). Precipitates of a geothermal or thermal energy storage system are usually investigated by analyzing the occurring scalings (see e.g., Wanner et al. 2017). On the other hand, there are only very few studies addressing crystallization processes or the particle load of geothermal water (Ueckert 2016; Wolfgramm et al. 2011). As a consequence, little is

show abstract

“…The formation is a carbonate-karstified groundwater aquifer which attains a vertical thickness up to 600 m (Prestel et al 1991). While the Pullach site takes advantage of the higher-fluid temperatures at the deepest parts of the aquifer for geothermal energy production (Baumann et al 2017), our work here centers on a carbonaceous aquifer in the northeastern part of the Bavarian Molasse Basin. Here, ambient temperatures are 22 • C, and have tight caprock formations above and below the aquifer (Dorsch and Pletl 2012;Fritzer et al 2014).…”

Section: Introductionmentioning

confidence: 99%

Porosity Dynamics through Carbonate-Reaction Kinetics in High-Temperature Aquifer Storage Applications

2021

View full text Add to dashboard Cite

While near-surface geothermal energy applications for the heating and cooling of buildings have been in use for decades, their practical adoption is limited by the energy transport rates through soils. Aquifers provide a means to use convective heat transport to improve heat transfer between the building and the aquifer. However, the solid matrix in the aquifer is carbonaceous in nature, and calcification prevention techniques in the heat exchangers for the building also lead to dissolution of the aquifer matrix. Due to the Arrhenius nature of the reaction, dissolution rates may decrease with increasing temperature. An effective medium model is derived for the energy, calcium species, and fluid transport through a dynamic calcite porous medium which undergoes a reaction between the matrix and fluid. To better discern how these competing phenomena affect thermal transport in the aquifer, a two-dimensional Cartesian system is considered, where the vertical axis is parallel to the borehole axis, and flow is in the horizontal direction. An effective medium model is derived for the energy, calcium species, and fluid transport through a dynamic calcite porous medium which undergoes a reaction between the matrix and fluid. Since the fluid velocity decays algebraically with radial distance from the borehole axis, two flow regimes are considered. In one regime, far from the borehole where flow rates are small, conductive thermal transport acts faster than the species transport, leading to a case where precipitation dominates and regions of the smallest porosity contract to limit energy recovery. In regions with larger porosity, moderate advection of the species is sufficient to prevent significant pore closures over the time scale of exploration. The second regime, closer to the borehole, larger flow rates reduce species concentrations sufficiently to dissolve the solid phase between pores. In this second regime, Taylor dispersion effects in both energy and species transport compete, but thermal conduction acts more slowly than advection, promoting dissolution. The critical limitation in modeling the long-term evolution of the aquifer structure is the in situ dissolution rate.

show abstract

Assessment of heat mining and hydrogeochemical reactions with data from a former geothermal injection well in the Malm Aquifer, Bavarian Molasse Basin, Germany

Cited by 15 publications

References 11 publications

Validation of hydrogeochemical databases for problems in deep geothermal energy

Validation of hydrogeochemical databases for problems in deep geothermal energy

Crystallization of calcium carbonate in a large-scale push–pull heat storage test in the Upper Jurassic carbonate aquifer

Porosity Dynamics through Carbonate-Reaction Kinetics in High-Temperature Aquifer Storage Applications

Contact Info

Product

Resources

About